The present invention relates to a remote-control method for a center facsimile device, and more particularly to a method for diagnosing and controlling a remote facsimile device by communicating with the facsimile device in a remote location using a non-standard format recommended by CCITT (the international telegraph and telephone consultative committee) regulation. Currently facsimile device are spread widely from businesses to homes, and they are on great demands nowadays. Further, ROM (Read Only Memory) versions of software and models of facsimile devices are becoming more diverse. Especially, the spread of low cost facsimile devices with no display devices such as liquid crystal display (hereafter referred to as LCD) window is increasing exponentially. Accordingly, it is increasingly expected that users will request the After-Service centers for confirming the telephone number, name and option setting of each remote facsimile devices. In prior art, when a problem arises during operation, or when the system malfunctions, an After-Service (hereinafter referred to as A/S) worker must visit each remote location to diagnose and repair the remote facsimile devices, thus causing higher service cost and longer service time.